CELLULAR FIXATION - A STUDY OF CYTORICH RED AND CYTOSPIN COLLECTION FLUID

OBJECTIVE: To test a new fixative system (Roche Image Analysis System, Inc. [RIAS]) that may create a background free of blood and blood pro ducts, and to determine if the CytoRich Red system has a potential for automation of nongynecologic cytology. We compared the amount of red blood cells, background material and diagnostic ability in 40 bloody s pecimens prepared using the CytoRich Red system and our routine fixati ve, Cytospin Collection Fluid (Shandon, Inc.). STUDY DESIGN: Thirty bl oody, nongynecologic specimens and 10 fresh FNA surgical specimens wer e prepared by adding specimen to equal volumes (10 mL) of CytoRich Red Fixative and Cytospin Collection Fluid. After initial centrifugation, the specimens were resuspended and cytocentrifuged using the Cytospin III (Shandon, Inc.) and the Hettich Universal cytocentrifuge. To rest system dependency, specimens from each fixative were prepared using t he alternate method of cytocentrifugation. Slides from both fixatives were stained, coverslipped and reviewed for the presence of red blood cells, background and diagnostic ability.RESULTS: Of the 40 CytoRich R ed specimens, 92.5% (37) had little or no red blood cells as compared to 22.5% (9) of the 40 Cytospin Collection Fluid specimens. Seventy fi ve percent (30) of the 40 CytoRich Red specimens showed reduction of b ackground material in contrast to 15% (6) of the 40 Cytospin Collectio n Fluid specimens. Diagnostic ability using CytoRich Red was enhanced by the reduction of red blood cells and background material. CytoRich Red performed equally as well with each cytocentrifugation device. CON CLUSION: CytoRich Red reduces red blood cells and background. Nuclear and cytoplasmic stain appear improved. This allows better evaluation o f the cytologic features and interpretation of bloody specimens. It is non-system dependent and can be used with any method of preparation. Also, the reduction of background and blood lends itself to adaptation in the automation of nongynecologic cytology.